The present disclosure relates generally to information handling systems, and more particularly to performing a warm reboot process in information handling systems that utilize the spanning tree protocol.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Some information handling systems such as, for example, switch devices in networks, utilize the spanning tree protocol in order to build a logical, loop-free topology in those networks. For example, the spanning tree protocol may operate to create a spanning tree within a network of switch devices that operate as connected layer-2 bridges by disabling links that are not part of the spanning tree in order to leave a single active path between any two network nodes. However, the use of the spanning tree protocol can raise some issues in some situations such as, for example, when control plane software in the switch devices undergoes a “warm reboot” by resetting, restarting, or otherwise re-initializing. In response to such a warm reboot, the spanning tree protocol port states that are programmed in port hardware in the switch device remain the same until the control plane software is finished re-initializing and, once reinitialized, the spanning tree protocol causes port state machines to run, port role/states to be calculated, and the port hardware to be programmed. However, the warm reboot completion time for the switch device can be more than three times the root bridge switch device hello time (e.g., the time between each bridge protocol data unit (BPDU) sent on the root bridge switch device ports, typically set to 2 seconds), which can cause peer switch devices that has learned root information from a switch device that is undergoing a warm reboot process to assume they are no longer connected to a root bridge switch device and, in response, open up their ports and cause a resulting traffic loop. Furthermore, after warm reboot, the spanning tree protocol restarts the spanning tree port state machines, which can lead to network traffic disturbances (e.g., when port role/states are recalculated and ports that should be open are blocked.)
Accordingly, it would be desirable to provide an improved spanning tree protocol warm reboot system.